Added changelog generator script and configuration. (#289)

Author: jorgecarleitao

.github_changelog_generator

@@ -0,0 +1,29 @@
+#!/bin/bash
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+# point to the old changelog in apache/arrow
+front-matter=For older versions, see [apache/arrow/CHANGELOG.md](https://github.com/apache/arrow/blob/master/CHANGELOG.md)\n
+# some issues are just documentation
+add-sections={"documentation":{"prefix":"**Documentation updates:**","labels":["documentation"]}}
+# uncomment to not show PRs. TBD if we shown them or not.
+#pull-requests=false
+# so that the component is shown associated with the issue
+issue-line-labels=arrow,parquet,arrow-flight
+exclude-labels=development-process,invalid